Capacity-constrained production-inventory systems : using Laplace transforms and input-output analysis

Sammanfattning: This thesis addresses issues in production-inventory systems in both a traditional and in e-business context, with an emphasis on capacity considerations. The general aim of the thesis is to model capacity-constrained production-inventory systems and thereby provide theoretical frameworks for control as well as design of these systems. This research has been conducted in two different contexts. In the traditional context, an ive survey of the literature on capacity-constrained production-inventory systems. The research has been conducted in two different contexts. In the traditional context, an extensive survey of the literature on capacity-constrained production-inventory systems irst presented. Production-inventory systems with capacity limitations are then modelled using the Laplace transform and input-output analysis for deterministic and stochastic demand situations, respectively. In the formulation of the model for the deterministic demand situations, the focus is on the way in which the fundamental balance equations for inventory and backlogs need to be modified. In the formulation for stochastic demand situations, the model extends previous theory in the direction of capacity considerations combined with uncertainty in external demand. The results of modelling and analysis in the traditional context contribute to development of a theoretical background for production-inventory system control applying the Laplace ransform approach and input-output analysis. In the e-business context, those aspects which are affected by e-business based customer ordering systems, and hence influence production-inventory systems, are studied. A nathematical model based on the assumption of a simple e-business model of direct sales channels is presented. Since e-business significantly facilitates customisation, models of two different production systems which consider customisation are provided. The production-inventory systems are then developed into an extended system where customers are included. For this system, a multiple objective formulation is obtained, in view of the importance of customers. The results of the modelling and analysis in the e-business context contribute insights and perspectives on ways to design and control e-business influenced production- inventory systems.